1、Good Material: Forged with high quality stainless steel material with high hardness and good durability against wearing and long use. 2、Easy Cutting: You can use a metal cutting blade to cut the hex shaft to the length you need according to your own needs, very convenient. 3、Hex Shaft Bar: Has an M4 threaded hole at both end. The outer diameter is 8mm, and the appearance is a hex with a plane spacing of 7mm. A perfect combination of round shaft and hex. 4、Practical Use: Can effectively prevent the parts from rotating and slipping, and makes the force more even. Greatly increases friction and transmission for driving efficiency. 5、Broad Utility: Used as a drive shaft for intelligent robots, and can also be applied to lathe equipment, engineering equipment and so on.